At dusk, the melancholy sound of the morepork (Ninox novaeseelandiae) can be heard in forests and parks as it calls to other moreporks and claims territory. Its European name (morepork), Māori name (ruru) and Australian name (boobook) all echo its two-part cry.
The morepork is New Zealand’s only surviving native owl. They are found in mainland New Zealand’s forests and on many offshore islands. They are less common in the drier, more open regions of Canterbury and Otago. Speckled dark brown, with yellow eyes and long tails, they are around 29 centimetres long from head to tail and 175 grams in weight. Another morepork subspecies lives on Norfolk Island. It was reduced in numbers to a single female, but after two males were introduced from New Zealand in 1987, a hybrid population was re-established.
The larger laughing owl became extinct in the 20th century. The German or little owl is a smaller introduced species.
Birds such as robins, grey warblers and fantails can end up as prey for moreporks. During the day, these small birds sometimes mob drowsy moreporks and chase them away from their roosts. Their noisy mobbing calls force the sleepy predators to search for a more peaceful spot.
During the day, moreporks sleep in roosts. By night they hunt a variety of animals – mainly large invertebrates including scarab and huhu beetles, moths and caterpillars, wētā and spiders. They also take small birds, rats and mice. They can find suitable food in pine forests as well as native forest.
Moreporks have soft fringes on the edge of their feathers, so they can fly almost silently and not alert potential prey. This also allows moreporks to hear the movements of their prey as they approach, rather than the noise of their own wings. They have acute hearing and their large eyes are very sensitive to light.
A morepork uses its sharp talons to catch or stun its prey, which it carries in its bill. Moreporks are canny hunters, as observed by ornithologist David Mudge:
I watched one pair visit the nests of three hapless starlings who had made the mistake of nesting in the same tree as the owls. The moreporks would go from one starling’s nest to the next, hovering outside and reaching in with their talons, feeling for young birds to grab. I have seen a pair of moreporks ferry seven chicks back to their nest in 15 minutes. 1
Moreporks nest in tree hollows, in clumps of epiphytes (perching plants), or in cavities among rocks and roots. The female lays up to three white eggs, usually between October and November, which she incubates for 20 to 30 days. During this time she rarely hunts, and the male brings food to her. Once the chicks hatch she stays mainly on the nest until the young owls are fully feathered. They can fly at about 35 days.
Scientists trying to establish a population of rare shore plovers on Motuora Island in the Hauraki Gulf were mystified as to why only two birds survived out of 75 placed there. The culprits turned out to be five pairs of moreporks that ate or chased away the new arrivals.
In Māori tradition, the morepork or ruru was often seen as a watchful guardian. As a bird of the night, it was associated with the spirit world. Its occasional high, piercing call signified bad news, such as a death, but the more common ‘ruru’ call heralded good news.
A number of sayings referred to the birds’ alertness. One saying warned an enemy that they were being watched:
Etia anō āku mata me te mata-ā-ruru e tīwai ana
Me te mata kāhu e paro noa rā kai te tahora!
My eyes are like morepork eyes turning from side to side,
Like the eyes of a hawk who soars over the plain! 2